/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.dadacoalition.yedit.preferences.tasktag;

import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;

/**
 * Dialog field containing a label and a combo control.
 */
public class ComboDialogField extends DialogField {
        
    private String fText;
    private int fSelectionIndex;
    private String[] fItems;
    private Combo fComboControl;
    private ModifyListener fModifyListener;
    private int fFlags;
    
    public ComboDialogField(int flags) {
        super();
        fText= ""; //$NON-NLS-1$
        fItems= new String[0];
        fFlags= flags;
        fSelectionIndex= -1;
    }
            
    // ------- layout helpers
        
    /*
     * @see DialogField#doFillIntoGrid
     */
    @Override
    public Control[] doFillIntoGrid(Composite parent, int nColumns) {
        assertEnoughColumns(nColumns);
        
        Label label= getLabelControl(parent);
        label.setLayoutData(gridDataForLabel(1));
        Combo combo= getComboControl(parent);
        combo.setLayoutData(gridDataForCombo(nColumns - 1));
        
        return new Control[] { label, combo };
    } 

    /*
     * @see DialogField#getNumberOfControls
     */
    @Override
    public int getNumberOfControls() {
        return 2;   
    }
    
    protected static GridData gridDataForCombo(int span) {
        GridData gd= new GridData();
        gd.horizontalAlignment= GridData.FILL;
        gd.grabExcessHorizontalSpace= false;
        gd.horizontalSpan= span;
        return gd;
    }   
    
    // ------- focus methods
    
    /*
     * @see DialogField#setFocus
     */
    @Override
    public boolean setFocus() {
        if (isOkToUse(fComboControl)) {
            fComboControl.setFocus();
        }
        return true;
    }
        
    // ------- ui creation          

    /**
     * Creates or returns the created combo control.
     * @param parent The parent composite or <code>null</code> when the widget has
     * already been created.
     */     
    public Combo getComboControl(Composite parent) {
        if (fComboControl == null) {
            assertCompositeNotNull(parent);
            fModifyListener= new ModifyListener() {

                public void modifyText(ModifyEvent e) {
                    doModifyText(e);
                }
            };
            SelectionListener selectionListener= new SelectionListener() {

                public void widgetSelected(SelectionEvent e) {
                    doSelectionChanged(e);
                }
                

                public void widgetDefaultSelected(SelectionEvent e) {   }
            };
            
            fComboControl= new Combo(parent, fFlags);
            // moved up due to 1GEUNW2
            fComboControl.setItems(fItems);
            if (fSelectionIndex != -1) {
                fComboControl.select(fSelectionIndex);
            } else {
                fComboControl.setText(fText);
            }
            fComboControl.setFont(parent.getFont());
            fComboControl.addModifyListener(fModifyListener);
            fComboControl.addSelectionListener(selectionListener);
            fComboControl.setEnabled(isEnabled());
        }
        return fComboControl;
    }   
    
    protected void doModifyText(ModifyEvent e) {
        if (isOkToUse(fComboControl)) {
            fText= fComboControl.getText();
            fSelectionIndex= fComboControl.getSelectionIndex();
        }
        dialogFieldChanged();
    }
    
    protected void doSelectionChanged(SelectionEvent e) {
        if (isOkToUse(fComboControl)) {
            fItems= fComboControl.getItems();
            fText= fComboControl.getText();
            fSelectionIndex= fComboControl.getSelectionIndex();
        }
        dialogFieldChanged();   
    }
    
    // ------ enable / disable management
    
    /*
     * @see DialogField#updateEnableState
     */     
    @Override
    protected void updateEnableState() {
        super.updateEnableState();      
        if (isOkToUse(fComboControl)) {
            fComboControl.setEnabled(isEnabled());
        }   
    }       
        
    // ------ text access 
    
    /**
     * Gets the combo items.
     */ 
    public String[] getItems() {
        return fItems;
    }
    
    /**
     * Sets the combo items. Triggers a dialog-changed event.
     */
    public void setItems(String[] items) {
        fItems= items;
        if (isOkToUse(fComboControl)) {
            fComboControl.setItems(items);
        }
        dialogFieldChanged();
    }
    
    /**
     * Gets the text.
     */ 
    public String getText() {
        return fText;
    }
    
    /**
     * Sets the text. Triggers a dialog-changed event.
     */
    public void setText(String text) {
        fText= text;
        if (isOkToUse(fComboControl)) {
            fComboControl.setText(text);
        } else {
            dialogFieldChanged();
        }   
    }

    /**
     * Selects an item.
     */ 
    public void selectItem(int index) {
        if (isOkToUse(fComboControl)) {
            fComboControl.select(index);
        } else {
            if (index >= 0 && index < fItems.length) {
                fText= fItems[index];
                fSelectionIndex= index; 
            }
        }
        dialogFieldChanged();
    }
    
    public int getSelectionIndex() {
        return fSelectionIndex;
    }
    

    /**
     * Sets the text without triggering a dialog-changed event.
     */
    public void setTextWithoutUpdate(String text) {
        fText= text;
        if (isOkToUse(fComboControl)) {
            fComboControl.removeModifyListener(fModifyListener);
            fComboControl.setText(text);
            fComboControl.addModifyListener(fModifyListener);
        }
    }
    
}

